The tank-like Nine-banded Armadillo's range has greatly expanded northward in the last 100 years. In the mid-1800s it was found only as far north as southern Texas; by the 1970s it lived in Oklahoma, Kansas, Missouri and Tennessee; now it’s also on the East Coast. Armadillos are typically active at night or twilight. They shuffle along slowly, using their sense of smell to find food—mostly insects, and occasionally worms, snails, eggs, amphibians, and berries. They root and dig with their nose and powerful forefeet to unearth insects or build a burrow. They always give birth to identical, same-sex quadruplets that develop from a single fertilized egg. Only two mammals are known to get a disease called leprosy: humans and armadillos. This has made armadillos important in medical research.